- 行业: Earth science
- Number of terms: 93452
- Number of blossaries: 0
- Company Profile:
Founded in 1941, the American Congress on Surveying and Mapping (ACSM) is an international association representing the interests of professionals in surveying, mapping and communicating spatial data relating to the Earth's surface. Today, ACSM's members include more than 7,000 surveyors, ...
A factor used, in the prediction of tides, to resolve the difference between chart datum of the reference station and chart datum of a secondary station.
Industry:Earth science
A datum defining a coordinate system which is used only over a region of very limited extent.
Industry:Earth science
(1) A corner (a) of which the original or restored monument or mark is recovered, or (b) the location of which was definitely established by one or more witness corners or reference monuments. (2) An existent corner of the public lands surveys which has been recovered by investigation in the field.
Industry:Earth science
One of a set of N coordinates, in N dimensional space, consisting of a distance r, and azimuth θ, and N-2 latitude like angles φ1, φ2, φ3, . . . φN-2. If the rectangular, Cartesian coordinates of a point are x<sub>1</sub>, x<sub>2</sub>, x<sub>3</sub>, . . . x<sub>N</sub>, then the corresponding generalized spherical coordinates are given by<br>
Industry:Earth science
A non-uniform contour interval. It may result because cartographic sources were used which contained different contour intervals, or it may result because the contour interval was adapted to best show the differences of elevation in different types of terrain.
Industry:Earth science
Any legal document that affects the ownership or use of public lands or resources.
Industry:Earth science
(1) Any coordinate system with origin at a specified and defined center of the Earth as, for example, the center of mass or the geometric center. (2) A coordinate system with origin at some point called the center of the Earth but otherwise left poorly or incorrectly defined. (3) A spherical coordinate system using the complement of the angle from the z-axis instead of the angle from the z-axis. It consists of a plane (called the equatorial plane) and a line (called the polar axis) perpendicular to the equatorial plane at a point (called the origin). The geocentric coordinates of a point are the distance of the point from the origin, the complement of the angle between the polar axis and the line joining the point to the origin, and the angle from a specified plane through the polar axis to a plane through the polar axis and the point in question.
Industry:Earth science
The curvature of the path taken by a narrow beam of electromagnetic radiation in passing through the atmosphere. The curvature is not constant but varies with altitude h. At each point of the path, the radius R of curvature is given, as a function of h, the index of refraction n at the point, and the angle θ that the path makes with the horizontal these, by R = -(n secθ)/(dn/dh).
Industry:Earth science
A point whose horizontal coordinates, or whose distance and direction to other points of like kind, are known accurately enough that they can be assumed known in further surveys.
Industry:Earth science
